Cement Production Processes (PDF)

How to produce What is cement? cement? Portland Cement 21-Oct-24  Early History of Cement In ancient times, egyptians mostly used material obtained by burning gypsum. Greeks and romans used the material obtained by burning lime stone. Fi...

How to produce What is cement? cement? Portland Cement 21-Oct-24  Early History of Cement In ancient times, egyptians mostly used material obtained by burning gypsum. Greeks and romans used the material obtained by burning lime stone. First cement was invented by Joseph Aspidin on 21st October 1824. First cement factory was started at Portland in England. 21-Oct-24  Portland Cement Cement can be hydraulic cement or non hydraulic cement. It is inorganic material which consists of oxides calcium, silicon, iron and aluminum. The hydration products act as binder to hold the aggregates together to form concrete. Portland cement is a hydraulic cement capable of setting, hardening and remaining stable under water. For non hydraulic cement, the products of hydration are not resistant to water (i.e.limestone) Cement is the mixture of calcareous, siliceous, argillaceous and other substances. Cement can be described as a material with adhesive and Cement is used as a binding material in mortar, cohesive properties that concrete, etc. used as a binding material 21-Oct-24  Raw Materials for Cement Manufacture Made by mixing calcareous substances, which containing Calcium Carbonate such as limestone, with argillaceous substances, which containing silica , alumina and iron oxide such as clay. Chemical composition of the raw materials: Argillaceous substances Calcareous substances Clay/shale Limestone/chalk SiO2 Silica (silicon oxide) CaC03 Calcium carbonate Fe203 Ferrite (iron oxide) Al203Alumina (aluminium oxide) Calcium Iron Silica Alumina Sulfate Sources of Calcite Blast-furnace Clay Aluminum-ore Anhydrit Raw Cement-kiln flue dust Fly refuse e Materials for dust Clay ash Clay Calcium Cement Chalk Iron Marl Fly sulfate Manufacture Limestone ore Rice-hull ash Gypsum Marl Mill ash Sand Shale Seashells scale Sandstone Slate Shale Shale Slag 21-Oct-24 Source: PCA, 2003 Manufacturing of Portland cement 1. Crushing and grinding of raw materials –Calcium Oxide (calcareous material) limestone, chalk, or oyster shells Cement clinker –Silica & Alumina (argillaceous material) clay, shale, blast furnace slag 2.Heat and melt in a kiln at 1400-1650oC (2500-3000oF) which forms cement clinker. Gypsum Source: PCA, 2003 3.Add gypsum (delays set time) to clinker and grind to fine powder particles small Cement grain – small particles produce a large surface area for more complete hydration 21-Oct-24  Flow chart of Portland cement manufacturing process 1. Grinding and mixing process 2. Heating process Dry process Mixing and crushing of Wet raw material process: process ▪ Dry process ▪ Wet process * Both (dry and wet) processes are to change the raw materials to 3. Addition of fine powder Gypsum & grinding process 21-Oct-24  1. Grinding and mixing process 2. Heating process 3. Addition of Gypsum & grinding process Mamlouk/Zaniewski, Materials for Civil and Construction Engineers, Third Edition. Copyright © 2011 Pearson Education, Inc. 21-Oct-24  Dry process Wet process In this process calcareous material such as In this process, the raw materials are changed limestone (calcium carbonate) and argillaceous to powdered form in the presence of water. material such as clay are ground separately to In this process, raw materials are pulverized by fine powder in the absence of water. using a Ball mill, which is a rotary steel cylinder Then, the materials are mixed with hardened steel balls. When the mill rotates, together in the desired steel balls pulverize the raw materials which form proportions. slurry (liquid mixture). Water is then added to it for getting thick The slurry is then passed into storage tanks, where paste and then its cakes are formed, dried correct proportioning is done. Proper composition and burnt in kilns. of raw materials can be ensured by using wet process than dry process. Corrected slurry is then fed into rotary kiln for burning. This process is usually used when raw materials are very This process is generally used when raw materials are strong and hard. In this process, the raw materials are soft changed to powdered form in the absence of water. because complete mixing is not possible unless water is added. 21-Oct-24  Heating process During the burning process: ▪ Decomposition of raw materials, calcareous Carbon emission substances CaCO3 ----→ CaO + CO2 Output from burning process ▪ This process changes the raw mix into cement clinker. ▪ Portland clinker consist of main mineral compounds: Calcium silicates Cement Clinker o tricalcium silicate (C3S) o dicalcium silicate (C2S) Calcium aluminates o tricalcium aluminate (C3A) Alumino ferites o tetracalcium aluminoferrite (C4AF) 21-Oct-24  3. Grinding Cooled clinkers are ground to fine powder in ball mills. At final stages of grounding, about 2-3% of powdered gypsum is added. This is to avoid setting of cement quickly when it comes in contact with water) Gypsum acts as a retarding agent for early setting of cement. 4. Packing Ground cement is stored in silos. From silos they are packaged into bag. 21-Oct-24  Functions of Cement Manufacturing Constituents Lime (CaO): Lime forms nearly two-third (2/3) of the cement. Therefore, sufficient quantity of the lime must be in the raw materials for the manufacturing of cement. Its proportion has an important effect on the cement. Sufficient quantity of lime forms di- calcium silicate (C2S) and tri-calcium silicate (C3S) in the manufacturing of cement. Lime in excess, causes the cement to expand and disintegrate. Silica (SiO2): The quantity of silica should be enough to form di-calcium silicate (C2S) and tri-calcium silicate (C3S) in the manufacturing of cement. Silica gives strength to the cement. Silica in excess causes the cement to set slowly. Alumina (Al2O3): Alumina supports to set quickly to the cement. It also lowers the clinkering temperature. Alumina in excess, reduces the strength of the cement. Iron Oxide (Fe2O3): Iron oxide gives colour to the cement. Magnesia (MgO): It also helps in giving colour to the cement. Magnesium in excess makes the cement unsound. Calcium Sulphate (or) At the final stage of manufacturing, gypsum is added to increase the setting of Gypsum (Ca SO4) cement. 21-Oct-24 Composition of Cement Clinker Main compounds: –tricalcium silicate (C3S) –dicalcium silicate (C2S) –tricalcium aluminate (C3A) –tetracalcium aluminoferrite (C4AF) 21-Oct-24 FUNCTION OF MAIN COMPOUND COMPOSITION The 4 main mineral compound are: Dicalcium Silicate (C2S) Slow strength gain – responsible for long-term strength 15-30% (Approximately percentage in OPC) 260 (J/g) – Heat of hydration Tricalcium Silicate (C3S) Rapid strength gain – responsible for early strength (eg: 7 days) Cement 45-60% (Approximately percentage in OPC) Clinker 500 J/g (Heat of hydration) Tricalcium Aluminate (C3A) Quick setting (controlled by gypsum); susceptible to sulphate attack 6-12% (Approximately percentage in OPC) 865 J/g (Heat of hydration) Tetracalcium Aluminoferrite (C4AF) From alumina & iron Little contribution to setting or strength; responsible for grey colour of OPC 6-8% (Approximately percentage in OPC) 420J/g (Heat of hydration) 21-Oct-24  Cement Reaction With Water Hydration of Portland Cement In the presence of water, the cement compounds chemically C3S + 3H --> C-S-H + 2CaOH combined with water (hydrate) to form new compounds that are rigid gel calcium the infrastructure of the hardened cement paste in concrete. hydroxide Both C3S and C2S hydrate to form calcium hydroxide and calcium silicate hydrate (CSH). Hydrated cement paste contains: C2S + 2H --> C-S-H + CaOH ✓ 15% to 25% Calcium hydroxide ✓ about 50% Calcium silicate hydrate by mass. rigid gel calcium **The strength and other properties of hydrated cement are hydroxide due primarily to calcium silicate hydrate. C3A reacts with water and calcium hydroxide to form C3A , C4AF have less hydraulic tetracalcium aluminate hydrate. properties but useful for liquid formation in kiln. C4AF reacts with water and calcium hydroxide to form calcium aluminoferrite hydrate. H - H2O As the hydration proceeds, the deposits of hydrated products on the original cement grains makes the diffusion of water to unhydrated nucleus more & more difficult. Thus, the rate of hydration decreases unhydrated with time & as a result hydration may take several years. hydrated depth of 5.2µ in three months and after 1 year it reaches 8 Hydrated products µm 21-Oct-24  Major compounds start to produce: Calcium-silicate-hydrate gels Calcium hydroxide Calcium-alumino-sulfohydrates 21-Oct-24 Detail primary chemical reactions during hydration C3S, C2S the most important, contribute reactivity of Portland Cement most of pyhsical properties of concrete *C3A is undesirable, contribute little or nothing in strength, except at early ages. Increasing the fineness of cement, increases the quantity of C3A, thus raises the gypsum requirement. 21-Oct-24 Hydration Product At any stage of hydration the hardened cement paste (hcp) consists of: Hydrates of various compounds referred to collectively as GEL, structure of hydrated cement. Crystals of calcium hydroxide (CH). Some minor compound hydrates. Unhydrated cement The residual of water filled spaces – pores/voids 21-Oct-24 Hydration Product (cont’d) Hydration Product (cont’d) Hydration Product (cont’d) Hydration Product (cont’d) Hydration Product (cont’d) Hydration Product (cont’d)  Smaller cement particles have more surface area to react with water Fineness fineness controls the rate of hydration (heat & strength gain) too fine is more expensive and can be harmful ❖ Fineness of cement is a measure of the sizes particles of cement. ❖ It is expressed in terms of specific surface of cement. ❖ Process of Hydration Since hydration starts at the surface of the cement particles it is the total surface area of cement that represents the material available for hydration The finer the cement is ground, the greater will be its specific surface. So the rate of hydration depends on the fineness of cement particles & for rapid development of strength higher fineness necessary. Fineness cement leads to a stronger reaction with alkali reaction aggregate & makes a paste though not necessarily concrete, exhibiting a higher shrinkage & a creates proneness to cracking. However, fine cement bleed less than a coarse one. The fineness is the most important factor which determines the properties of cement: Finer grinding increases the speed with which the various constituents reacts with the water Fineness of grinding is of some importance in relation on the workability of concrete mixes. Greater fineness increases the cohesiveness of a concrete mix Finer grinding reduces the chances of bleeding of concrete In some special type of cement the strength increases slowly than normal though they 21-Oct-24 are finely grounded. Cement + Water Thus, the following actions occur: (1) hydration process and (2) setting (2) Setting When cement is mixed with sufficient water, it loses its plasticity and slowly - Initial set: Initially the paste loses its forms into a hard rock-type material; this fluidity and within a few hours a whole process is called setting. noticeable hardening occurs - Hydration of C3S & C 2S: Measured by Vicat’s apparatus produces C-S-H (calcium- - Final set: Further to building up of hydration products is the common silicate-hydrate) → makes cement of hardening process that is paste strong responsible for strength of concrete - Primary Chemical Reaction Measured by Vicat’s apparatus Chemical reactions that harden cement paste “Hardening” – is not setting or drying Fast in the beginning but is Drying = evaporation = no water long term (decades in dams) – stops reaction Causes heat, which can be – stops strength gain a problem if there’s too much Structure development in 21-Oct-24 cement paste  Cement Reaction With (1) Hydration of Cement Water In the presence of water the cement compounds chemically combined with water C3S + 3H --> C-S-H + 2C-H (hydrate) to form new compounds that are the infrastructure of the hardened cement paste in rigid gel concrete. Both C3S and C2S hydrate to form calcium C2S + 2H --> C-S-H + C-H hydroxide and calcium silicate hydrate (CSH). rigid gel Hydrated cement paste contains 15% to 25% Calcium hydroxide and about 50% calcium C3A , C4AF have less silicate hydrate by mass. The strength and hydraulic properties but other properties of hydrated cement are due useful for liquid primarily to calcium silicate hydrate. formation in kiln. C3A reacts with water and calcium hydroxide to form tetracalcium aluminate hydrate. C - CaO , H - H2O C4AF reacts with water and calcium hydroxide to form calcium aluminoferrite hydrate. For all the Portland cement compound hydration reactions see Table 2-5: https://www.youtube.com/watch?v=k02f 21-Oct-24 OFB2-iQ HEAT OF HYDRATION Hydration process of cement is accompanied by heat generation (exothermic). As concrete is a fair insulator, the generated heat in mass concrete may result in expansion & cracking. This could be overcome by using suitable cement type. It could also be advantages for cold wheather concreting. The heat of hydration of OPC is on the order of 85-100 cal/gr. About 50% of this heat is liberated within 1-3 days & 75% within 7 days. By limiting C3S & C3A content heat of hydration can be reduced. 21-Oct-24  Hydration of cement Heat is liberated as cement sets and hardened by reacting with water. The rate of heat evolution as well as total heat depends on the compositon of cement. The rate of hydration & the heat evolved increases with the fineness of cement but the total amount of heat liberated in unaffected by fineness. C3S Hydration C3A Hydration 21-Oct-24 Hydration of cement (cont’d) Stage 2 Portland cement concrete remains in plastic state for several hours. Initial set occurs in 2-4 hours, about the time C3S has begun to react again. 21-Oct-24 Hydration of cement (cont’d) Stage 3 The reactivity reaching a maximum rate at the A steady end of the acceleration state period, which corresponds with the maximum rate of heat evolution. Early hardening begun 21-Oct-24 (1) Setting At the beginning of mixing, the paste has a structure which consists of cement particles with water-filled space between them. As hydration proceeds, the gels are formed & they occupy some of this space. 1cc of cement → 2.1cc of gel 21-Oct-24 21-Oct-24 21-Oct-24  Properties of Hydrated Cement (1)Fineness Test (2)Setting Time (3)Compressive Strength 21-Oct-24 (1) Fineness Test: Properties of Hydrated Cement (cont’d) Finer cements react quicker with water and develop early strength, though the ultimate strength is not affected. However finer cements increase the shrinkage and cracking of concrete. The fineness is tested by: By Sieve analysis: Break with hands any lumps present in 100 grams of cement placed in IS sieve No.9 and sieve it by gentle motion of the wrist for 15 minutes continuously. The residue when weighed should not exceed 10 percent by weight of the cement sample. Blaine test – Measures air permeability against known 21-Oct-24 standard material (2) Setting time Properties of Hydrated Cement (cont’d) The time from the addition of water to the initial & final setting stage. Also refers to time of changes of the cement paste from a liquid to a rigid stage. The setting process is accompanied by the temperature changes, hydration resolves in the formation of the gel around each parties of cement. The means of controlling the rate at which cement stiffened by intergrinding a measured quantities of gypsum Initial Setting Defined as the beginning of the noticeable stiffening in the cement paste. It’s corresponds to a rapid rise in temperature. Normally takes about 45 – 175 minutes. Final Setting Time Refers to completion of setting, which corresponds to the peak temperature in the cement paste. The stiffening of cement paste increases as the volume of the gel increases and the stage at which this is complete, the final hardening process begins. Normally takes between 3 hours to 10 hours for this to happen. Hardening Referred to the gained of the strength of the cement paste. 21-Oct-24 During the setting time the cement gained very little strength  Consistency Test /Setting Time Test : This test is performed to determine the quantity of water required to produce a cement paste of standard or normal consistency. Standard consistency of cement paste may be defined as the consistency which permits the Vicate’s plunger (10 mm, 40 to 50 mm in length) to penetrate to a point 5 mm to 7 mm from the bottom ( or 35 mm to 33 mm from top) of Vicat mould. When the cement paste is tested within the gauging time ( 3 to 5 minutes) after the cement is thoroughly mixed with water. Vicat apparatus is used for performing this test. 21-Oct-24  Setting Time Test: In cement hardening process, two instants are very important, i.e. initial setting and final setting. 21-Oct-24  Initial Setting Time: The process elapsing between the time when water is added to the cement and the time at which the needle ( 1 mm square or 1.13 mm dia., 50 mm in length) fails to pierce the test block ( 80 mm dia. and 40 mm high) by about 5 mm, is known as Initial Setting Time of Cement. 21-Oct-24 Final Setting Time: The process elapsing between the time when water is added to the cement and the time at which a needle used for testing final setting upon applying gently to the surface of the test block, makes an impression thereon, while the attachment of the needle fails to do so, is known as final Setting Time of Cement. 21-Oct-24  Tests for Initial and Final Set penetration of weighted needle Vicat Gillmore 21-Oct-24 Mamlouk/Zaniewski, Materials for Civil and Construction Engineers, Third Edition. Copyright © 2011 Pearson Education, Inc. 86  Compressive Strength ASTM C109 Average of three 50X50X50 mm cubes Compressive strength of concrete cannot be accurately predicted from cement strength Mold Compression Prepare sample test Typical failure Mamlouk/Zaniewski, Materials for Civil and Construction Engineers, Third Edition. Copyright © 2011 Pearson Education, Inc. 42 (3) Compressive Strength test of Cement: This test is very important. In this test, three moulds of (face area 50 cm2) are prepared and cured under standard temperature conditions and each cube tested by placing it between movable jaws of the compressive strength testing machine. The rate of increasing load is zero in the beginning and varies at 350 kg/cm2 per minute. The load at which the cube gets fractured divided by the cross sectional area of the cube, is the compressive strength of the cube. The average of the compressive strengths of three cubes is the required compressive strength of the cement sample. 21-Oct-24 Admixture vs Additive ❑Admixture: chemical admixture and mineral admixture ❑Admixture implies addition at the mixing stage whereas additive refers to a substance which is added at the cement manufacturing stage. ❑Mineral admixture also known as mineral additive, which also known as pozzolana  Admixtures ❑ Mineral admixture also known as mineral additive ❑ These materials are other than cement, aggregate and water, that are added to concrete either before/during its mixing to alter its properties Mineral admixture Chemical admixture  Pozzolana The name Pozzolana comes from the town Pozzuoli, Italy. Ancient Romans (~100 B.C.) produced a hydraulic binder by mixing hydrated lime with soil (predominantly volcanic ash) From left: Fly ash (class C), metakaolin (calcined clay), silica fume, fly ash (class F), ggbs, calcined shale Source: PCA – Design and Control 14 th Edition a material that, when used in conjunction with portland cement, contributes to the properties of the hardened concrete Siliceous or siliceous and aluminous materials which through hydraulic or pozzolanic activity, by themselves possess no or both. cementing property, but in fine pulverized form and in the presence of water can Nowadays, the word pozzolan covers a react with lime in cement to broad range of natural and artificial form concrete materials.  Effect of Pozzolana ▪ Pozzolanic effect CH, by-product of cement hydration Filling Effect reacts chemically with SiO2/Al2O3 Filler, improving physical structure occupying spaces between the and generate CSH cement particles ▪ Physical micro particle effect Small particles are packing larger particles, filling voids and boundary zone, resulting in a denser cement matrix and improving the microstructure of concrete  Pozzolanic Reactions Primary Reaction Portland cement reactions Fast Calcium Silicates + Water -----> Calcium Silicate Hydrates + Calcium Hydroxides (C3S + C2S) NaOH Calcium hydroxide will remain NaOH active for opportunity to KOH chemical reactions. Secondary Reaction KOH Slow Pozzolana + Calcium Hydroxide + Water + -----> Calcium Silicate Hydrates Pozzolana : consist of SiO2 or Al2O3 or both Capacity of pozzolan to form cementitious products depends on the effectiveness of the pozzolana)  Why Pozzolana?? o Special performance is needed such as o Increase in strength, reduction in water demand, low heat of hydration. o Densify microstructure and reduce penetrability, improved durability. o Minimise segregagation, fill in porosity region around aggregates (ITZ) o For cost and energy savings: o Replacement of cement leads to cost savings; energy required to process these materials is also much lower than cement o Environmental issue: o Environmental damage and pollution is minimized by the use of these by-products o about 6 – 7% of total CO2 emission occurs from the production of cement o Availability and supply: o Usage depends on supply and demand forces, as well as the market potential and attitudes Application of Pozzolana ▪ Direct use Mixing pozzolana with Calcium Hydroxide Extensively used in ancient times but not very common now ▪ Producing blended cements Grinding “Clinker + Pozzolan + Gypsum”→ Portland Pozzolan Cements Extensively used It should be noted that latent hydraulic materials can replace Portland cement up to a much larger extent than materials showing pozzolanic behaviour only. ▪ Use as an Admixture “Cement + Pozzolan + Aggregate + Water”→ Concrete Typical Amounts of Pozzolans in Concrete by Mass of Cementing Materials Fly ash – Class C 15% to 40% – Class F 15% to 20% Slag 30% to 45% Silica fume 5% to 10% Calcined clay 15% to 35% – Metakaolin 10% to 15% Calcined shale 15% to 35%  Silica fume It is a product resulting from reduction of high purity quartz with coal in an electric arc furnace in the manufacture of silicon or ferrosilicon alloy. Micro silica is initially produced as an ultrafine undensified powder At least 85% SiO2 content Mean particle size between 0.1 and 0.2 micron Minimum specific surface area is 15,000 m2/kg Spherical particle shape 10  Silica fume (cont’d) Effect on fresh concrete Effect on hardened concrete The increase in water demand of concrete Modulus of elasticity of microsilica containing microsilica will be about 1% for concrete is less. every 1% of cement substituted. Improvement in durability of lead to lower slump but more cohesive mix. concrete. make the fresh concrete sticky in nature and Resistance against frost damage. hard to handle. Addition of silica fume in small large reduction in bleeding and concrete with quantities actually increases the microsilica could be handled and transported expansion. without segregation. to plastic shrinkage cracking and, therefore, Application sheet or mat curing should be considered. produces more heat of hydration at the Conserve cement initial stage of hydration. Produce ultra high strength concrete the total generation of heat will be less than of the order of 70 to 120 MPa. that of reference concrete. Increase early strength of fly concrete. Control alkali-aggregate reaction. Reduce sulfate attack & chloride associated corrosion. Fly ash Fly ash is finely divided residue resulting from the combustion of powdered coal and transported by the flue gases and collected by; Electrostatic Precipitator Fly ash is the most widely used pozzolanic material all over the world. Types of fly ash ◼ Class C ◼ Class F – Fly ash normally produced by burning lignite or sub- – Fly ash normally produced by bituminous coal. Some class C burning anthracite or fly ash may have CaO content in bituminous coal, usually has excess of 10%. In addition to less than 5% CaO. Class F fly pozzolanic properties, class C fly ash has pozzolanic properties ash also possesses cementitious only. properties.  High volume Fly Ash has been used in the Barker Hall Fly ash (cont’d) Project, University of California at Berkeley for the construction of shear walls. Effects of Fly Ash on Hardened Concrete contributes to the strength of concrete due to its pozzolanic reactivity. continued pozzolanic reactivity concrete develops greater strength at later age not at initial stage. contributes to making the texture of Application concrete dense, resulting in decrease of water permeability and gas permeability. Many high-rise buildings Industrial structures Water front structures Concrete roads Roller compacted concrete dams. In India, fly ash was used for the first time in the construction of Rihand Irrigation Project, Uttar Pradesh in 1962, replacing cement up to about 15 per cent  Blast furnace slag Blast-furnace slag is a nonmetallic product consisting essentially of silicates and aluminates of calcium and other bases. The molten slag is rapidly chilled by quenching in water to form a glassy sand like granulated material. The granulated material when further ground to less than 45 micron will have specific surface of about 400 to 600 m2/ kg (Blaine).  Blast furnace slag Effects on fresh concrete Effects on hardened concrete Reduces the unit water Reduced heat of hydration content necessary to obtain Refinement of pore the same slump. structures Water used for mixing is not Reduced permeabilities to immediately lost, as the the external agencies surface hydration of slag is Increased resistance to slightly slower than that of chemical attack. cement. Reduction of bleeding.  Metakaolin Highly reactive metakaolin is made by water processing to remove unreactive impurities to make100% reactive pozzolan. Such a product, white or cream in colour, purified, thermally activated is called High Reactive Metakaolin (HRM).  Metakaolin Effects of Metakaolin Use of Metakaolin High reactive metakaolin The high reactive shows high pozzolanic metakaolin is having the reactivity and reduction in potential to compete with Ca(OH)2 even as early as silica fume. one day. The cement paste undergoes distinct densification. Densification includes an increase in strength and decrease in permeability.  Rice husk ash Contains Rice husk ash is obtained by ◼ Amorphous silica (90% Burning rice husk in a SiO2) in very high controlled manner without proportion when burnt in causing environmental controlled manner. pollution. ◼ 5% carbon. Material of future as ◼ 2% K2O. mineral additives.  Rice husk Ash Improves overall resistance Effects to CO2 attack. Reduces susceptible to acid Enhances resistance to attack and improves resistance corrosion of steel in concrete. to chloride penetration. Reducing micro cracking and improving freeze-thaw resistance. Reduces large pores and Improves capillary suction and porosity resulting very low accelerated chloride diffusivity. permeability. Reduces the free lime present in the cement paste. Decreases the permeability of the system. Class task: 14 October 2024 American Standard (ASTM European (EN 197-1) British Standard C150) Type Classification Type Classification Ordinary Portland Type I General purpose CEM I Portland cement (BS 12) Modified cement Type II Moderate sulfate CEM II Portland-composite cement resistance Rapid-hardening Type III High early strength CEM III Blast furnace cement Portland (BS 12) Low-heat Portland Type Iv Low heat of hydration CEM IV Pozzolanic cement (BS1370) Sulfate Resisting Type V High sulfate resistance CEM V Composite cement Portland (BS 4027 Neville & Brooks (2010) READING ASSIGNMENT #1 What Why Example Class task: 14 October 2024 Date: 21 Oct 2024 Feedback from class task: List type of cement: what – define the cement, its fact, why – function, example – application of the cement ** the use of pozzolan as an alternative material for cement type performance in achieving the concrete performance